1. Field of the Present Invention
The invention relates a 5-layer co-extruded biaxial-oriented polypropylene synthetic paper; particularly the formula of composition of the material for making the laminated 5-layer co-extruded biaxial-oriented polypropylene synthetic paper which can improve the rigidity and stiffness, covering power, paper glossiness and printability of the conventional co-extruded biaxial-oriented polypropylene synthetic paper.
2. Description of Prior Act
During the recent 15 years the inventor of the present invention has devoted all the efforts in enhancing the quality of the 3-layer co-extrude biaxial-oriented polypropylene synthetic paper for the goal of using said synthetic paper to supersede natural paper, and has been granted many patents including U.S. Pat. Nos. 5,551,511; 6,001,290; 6,364,988 and 6,379,605.
However the 3-layer co-extruded biaxial-oriented polypropylene synthetic paper (20) commonly known in the past has a 3-layer laminated structure as depicted in FIG. 1 which comprises the uppermost layer (A1) of paper sheet or resin, the intermediate foamed layer (B1), and the bottom layer (C1) of paper sheet or resin.